A known gas bag for side impact protection has at least two inflatable chambers which are separated from each other in a gas-tight manner.
A gas bag module with such a gas bag for the protection of the pelvic and chest areas of a vehicle occupant is known from the EP-A-1 008 494. The two chambers of the gas bag, which are separated from each other by a seam, are filled with gas from a compressed gas source with a distributor housing such that the lower chamber, provided for protection of the pelvic area of the vehicle occupant, has a higher internal pressure than the upper chamber provided for the protection of the chest area of the vehicle occupant. With such a gas bag, however, care must be taken that the separating seam is not stressed too highly by the hot inflowing gas on inflation of the gas bag, and that the partial reduction of the thickness of the gas bag, necessitated by the separating seam, leads to a reduced protective effect in this region and as a whole leads to a reduction in the inherent rigidity of the gas bag compared with a corresponding gas bag without separating seam.
In the DE-A-100 20 920 there is shown a side impact protection device with a double gas bag. Inside a first gas bag for protection of the chest area of a vehicle occupant, a separate second gas bag is arranged for protection of the pelvic area of the vehicle occupant, which is inflated with a higher pressure than the first gas bag. This design requires a very costly production process, because the second gas bag has to be introduced through an opening of the first gas bag and subsequently sewn to it. The connection of the two gas bags can only take place in the external, i.e. visible area. A disadvantage with respect to the installation space is the at least four-layered structure in the region of the second gas bag, which requires a large storage space to house the double gas bag. Owing to the gas bag lying in the interior, in this region also no precisely defined folding (turning over etc.) is possible. In addition, the position of the gas generator arranged in the seat rest and provided for filling the gas bags, is subject to great restrictions owing to the special construction. Moving the installation position of the gas generator, owing to limited space conditions (if, for example, an arrangement for moving a lordosis support is additionally provided in the seat rest), is only possible with a high constructional expenditure in this system.
The invention provides a gas bag which is constructed in a compact manner, can be designed so as to be flexible and makes possible a simple realization of various pressure zones, adapted to the biomechanical characteristics of the parts of vehicle occupant's body, to protect the vehicle occupant in a side impact.